Radio energized lamp



Dec. 25, 1951 WALES, JR 2,579,989

' RADIO ENERGIZED LAMP 9 Filed Dec. 1, 1949 Tlql. v flMPL/F/EA GSCAMIWRINVENTOR.

Patented Dec. 25, 1951 UNITED STATES PATENT OFFICE 7 RADIO ENERGIZEDLAMP Nathaniel B. Wales, Jr., New York, N. Y.

Application December 1, 1949, Serial No. 130,421

1 Claim. (Cl. 315-188) This invention relates to a lighting device,especially a table lamp, in which the power for energizing the lamp istransmitted thereto by electromagnetic radiation.

This device is particularly useful in restaurants and public placeswhere the absence of power wires and the obscurity of its power sourceare valuable from convenience and novelty standpoints.

I In my invention I utilize a loop inductance in conjunction with acapacitance to form a tunable resonant circuit, preferably parallel, toenergize an electric light, preferably of the fluorescent gaseousdischarge type. The electromagnetic radiation for powering 'this lampmay be generated by a crystal-controlled oscillator-amplifier, operatingon some authorized industrial frequency, and radiated by a dipoleunobtrusively located near the ceiling of the restaurant or auditoriumto be lighted. In the preferred form of the invention I utilize theinductive loop as the mechanical support for this fluorescent lamp.'This double utility permits the linking of the radiation field by asubstantial aperture while occupying a minimum of table space for thelamp. In addition, the vertical plane of such a loop-support permits themaximum average energy transfer from a dipole elevated above such lamps,since the vertical plane of the loops may be made more closely tocoincide with a plane passing through the dipole than any other fixedgeometry of loop.

A third object is to make possible a radiopowered gaseous discharge lampwhich does not require excessive power for starting.

Other objects will appear in the specifications and claim.

Referring to the drawings:

Figure 1 is the schematic diagram of one form of radiating systemsuitable for energizing my invention;

Figure 2 shows a vertical section in elevation of the preferred form ofmy invention;

" denser 3 shown in Figure 2.

The preferred. type of radiator installation shown in Figure 1 consistsof a crystal-controlled oscillator I8 feeding a power amplifier H] whichin turn feeds the dipole elements 23 via the transmission line 20. Thewires 23 are secured to center insulator 2| and end insulators 22. Guywires 24 secure the end insulators 22 to the walls 26 by means ofscrew-eyes 25. It is desirable that the walls 26 and ceiling 21 be of ametal lath or other construction which will be reflective at thefrequency of oscillator I 8, so

9 that a minimum of radio-frequency energy is It is to be noted thatthis loop-support concept is equally applicable to a less preferred formof my invention utilizing a series resonant circuit in conjunction withan incandescent lamp.

A particularly valuable feature of the invention lies in the use of anauxiliary starting electrode external to the gaseous discharge tube andso positioned that, prior to the initial breakdown of the gases in thetube, there is a concentration of the oscillatory potentials appearingacross the resonant circuit applied through a small portion of theoperating gap of this discharge tube. This results in a very largedecrease in the power necessary to start the lamps over a givendistance, below that which would be required without this fieldconcentration. Evidently, this step makes the installation of such lampsmore practical from an equipment cost standpoint.

An object of this invention is to makepossible a remotely-powered lightsource having no wire connections.

A second object is to combine the elements of a large aperture resonantcircuit with the components of a table lamp with a minimum of parts.

radiated beyond the room to be lighted.

Such other precautions well-known to the art, such as the use of Faradayshields, push-pull stages, filtered power supplies, and no frequencydoubling, should be used to prevent the radiation of harmonics, therebyinsuring the confinement of the radiation to the authorized frequencyband (for instance, 27 megacycles).

The receiving lamp shown in Figures 2, 3, 4 and 5 consists of a circularmetal (copper) loop I passing through and secured to the base 2 which ispreferably made of a transparent plastic. This transparent constructionemphasizes the absence of concealed wires in the device.

Loop I within the scope of this invention may also be rectangular or ofany other artistically desirable shape as long as itsubtends an adequatearea and presents a sufiiciently high electrical Q to operate its lamp.A circular loop gives the maximum Q for this class of geometry.

The ends of loop I connect and are secured to the support leads or buses6 and 8 which in turn connect and are secured to the opposite end ter-9. Tube 9 is operated as a two electrode cold cathode discharge tube, asshown in Figure 4.

However, for convenience in availability, a

standard commercial hot cathode fluorescent 3 tube may be used in thecapacity of a cold cathode tube, as shown. In this case, it ispermissible to short circuit together the two pin terminals 10 on eachend, as shown in Figure 3, thereby using each of the two filamentcircuits on each end of such a tube as a single cold dischargeelectrode.

The conventional variable air condenser 3 consists of shaft 3, rotorplates I5, bushing it, knob 4 mounted on shaft 3, insulatingplate H,stator support [3 and stator plates Hi. This unit is secured between theends of the loop i by bracket l2 on one side and by stator support i3via bus 6 on the other side, thereby also making the parallel electricalconnection shown in Figure 4. The non-metallic truncated conical shade 5is secured to the insulating condenser plate H by screws ll, thuscompleting the lamp structure proper. Obviously, other forms of shadesor positions of the tube may be used under the scope of the invention.For instance the shade may be the segment of a small long cylinder andcover the tube-alone; or the segment of a short large cylinder and coverthe upper portion of the whole loop. Similarly, the tube may be radial(internally or externally) or normal to the plane of the loop.

The preferred means for causing a high space gradient of the potentialsappearing across the resonant circuit to be set up within a portion ofthe discharge tube for easy starting is shown in Figure 2 as theconductive rod 1 which comprises an extension of the support conductor8. This auxiliary electrode 1 terminates a short distance from the endof the tube opposite its junction with bus 6 and, consequently, a highgradient of the potentials across the parallel resonant circuit will beset up between the tip of electrode 1 through the glass wall of the tubeto the adjacent electrode within tube 9. This high local gradient willionize the gas within the tube at a far lower resonant peak potentialthan that needed to ionize gas using the gradient which would obtainacross the whole tube in the absence of auxiliary external electrode 1.Once electrode I has created local ions within the tube, cumulativeionization within the tube will cause the entire tube to break down,thus affording a low impedance path for the resonant currents, incontradistinction to the high impedance path offered through theinternal electrodes of the tube prior to breakdown.

Alternative to this particular execution of the invention, it is equallyoperable to form the leads 6 and 8 so that they are sufficientlyadjacent both to the glass wall of tube 9 and to one another as to applya concentrated field across a central portion'of the whole breakdown gapIll-40 (Figure 2) thereby achieving the same end. In either case,electrode means external to the discharge tube are utilizedto produce apotential gradient across a portion of the operating discharge gap.

What I claim is:

In a lamp structure adapted to be energized by absorbed radio-frequencyenergy, the combination comprising a lamp base, a substantially circularmetallic arc secured at its mid-portion to said base, the upwardlyextending arms of said are lying in a vertical planeand forming aninductive loop member for absorbing said radiofrequency energy, atubular gaseous discharge tube, two electrodes entering said tubulardischarge tube at opposite ends thereof, a metallic member for securingeach of said electrodes to the opposite ends of said arc whereby tosupport said tube and electrically connect it in parallel with saidinductive arc member, an adjustable capacitance connected in parallelwith said loop member, and a starting electrode located exterior to saiddischarge tube closely adjacent to one end thereof and electricallyconnected to that first said electrode lying at the opposite end of saiddischarge tube from said starting electrode.

NATHANIEL B. WALES, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

Clack Apr. 18. 1950

